Risk of comorbidity of autoimmune liver disease in patients with inflammatory bowel disease: A single‐center case–control study in China

Objective To investigate the prevalence of autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC), and the impact of comorbidity of AIH, PBC, and PSC on hospitalization burden in patients with inflammatory bowel disease (IBD). Methods Inpatients admitted to Peking Union Medical College Hospital from January 1, 1998 to December 31, 2021 were included. Odds ratio (OR) and the corresponding 95% confidence interval (CI) were calculated to compare the risk of AIH, PBC, and PSC between IBD and non‐IBD patients. Medical cost and length of hospitalization were compared between IBD patients with and without AIH, PBC, or PSC. Results Among the included 858 967 inpatients, there were 3059 patients with IBD. Additionally, there were 117 patients with AIH, 879 patients with PBC, and 35 patients with PSC, regardless of having IBD or not. Patients with IBD had a significantly higher risk of AIH (OR 4.87, 95% CI 1.20–19.71, p = 0.03) and PSC (OR 112.28, 95% CI 53.88–233.98, p < 0.01) than those without IBD. While there was no significant difference in the risk of PBC between patients with and without IBD (OR 1.60, 95% CI 0.67–3.86, p = 0.29). The medical cost of each hospitalization did not differ between IBD patients with and without AIH, PBC, or PSC. Conclusions IBD patients had a higher risk of AIH and PSC. Comorbidity of AIH, PBC, or PSC has no significant effect on the average cost of each hospitalization in IBD patients.